Case-based teaching systems, like good human teachers, tell stories in order to help students learn. A case-based teaching system engages a student in a challenging task and monitors his actions looking for opportunities to tell stories that will assist the learning process. In order to produce stories at the appropriate moment, a case-based teaching system must have a library of stories that are indexed according to how they should be used and a set of reminding strategies to retrieve stories when they are relevant. In this paper, I discuss CreANIMate, a biology tutor that uses stories to help teach elementary school students about animal morphology. In particular, I discuss the reminding strategies and indexing schemes that enable the system to achieve its educational objectives. These reminding strategies are example remindings, similarity-based remindings, and expectation violation remindings.